Expression of Renilla luciferase provides an internal control value to which expression of the experimental firefly luciferase reporter gene may be normalized

A T7 promoter is located immediately upstream of Rluc, allowing in vitro synthesis of Renilla luciferase

The SV40 late poly(A) signal sequence is positioned downstream of Rluc to provide efficient transcription termination and mRNA polyadenylation

In addition to the modified Rluc reporter gene, all pRL Vectors are isolated from a dam–/dcm– E. coli K host strain, allowing digestion with restriction enzymes that are sensitive to dam and dcm methylation

A prokaryotic origin of replication and β-lactamase gene allow selected propagation of the pRL vectors in E. coli host strains

Four different promoter configurations are available

The HSV-thymidine kinase promoter (pRL-TK) is relatively weak and may be particularly useful in providing neutral constitutive expression of the Renilla luciferase control reporter